Door latch unit



Sept. 18, 1951 J. n. CARROLL DooR LATCH UNIT Filed Feb. 14. 194e JOHN D. CA

@ROL L'V Patented Sept. 18, 1951 DOOR LATCH UNIT John D. Carroll, Kensington, Conn., assignor to The Stanley Works, New Britain, Conn., a corporation of Connecticut Application February 14, 1946, Serial No. 647,453

This invention relates to door latches of the type having a bolt spring-urged into latching position and a plunger extending through the door and through which the bolt is manually moved into open position.

An aim of the invention is to provide latches of this type with readily adjustable plungers, the plunger being so constructed and arranged that the latch mechanism and operating member may Ybe mounted on opposite sides of a door of any standard thickness and then, by merely pushing in on the operating member, the length of the plunger is automatically adjusted to the correct length. Thus, the necessity, heretofore required, of cutting off or otherwise fixing the length of the plunger prior to the installation of the latch mechanism and operating member upon the door is obviated.

A further aim of the invention is to provide a latch with an automatically adjustable plunger so that the latch mechanism and the handle may be installed on a door and the plunger automatically adjusted to proper length without the necessity for vmeasurements or removal of the latch mechanism after initial installation.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

' The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplied lin the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.

In the drawings- Figure l is an edge view partially in cross section of a door with a latch and latch handle installed thereon and embodying my invention;

Fig. 2 is a front end View of the sleeve or collet which comprises a portion of the latch actuating plunger;

Fig. 3 is a side view of the sleeve; and

Fig. 4 is a cross sectional view through the latch, the same being taken substantially on line 4--4 of Fig. 1.

Referring to the drawings in detail, there is shown, for illustrative purposes only, a latch of the type described in Patent No. 2,441,033, issued May 4, 1948 by Stuart W. Parsons and entitled Door Latch. The latch comprises a casing Il) secured to the inner surface of a door A in any suitable manner, as by means of screws I I. Pivoted at I2 in the casing is a two-piece bell-crank lever I3 which, in turn, is pivotally connected at .Ill'with a bolt I5 between the ends of the latter.

2 Claims. (Cl. 292-191) rection, referring to Fig. 4. This movement of the lever I3 is accomplished by pressing inwardly on a plunger having a yoke I'I pivoted to the lever I3 at I8. The plunger also comprises, as hereinafter described more in detail, a collet or sleeve 3D and a stem 3|.

The inner surface of the door has a recess I9 to accommodate the end of the yoke |'I and a through bore 26 extends from the recess to the outer surface of the door A. The collet 30 extends into the bore 20 and the stem 3| projects from the outer surface of the door.

Suitably mounted on the outside of the door is an operating member cooperating with the stem 3| for pushing the plunger inwardly to thereby move the bolt into unlatching position. In the present illustrative disclosure, this operating member is in the formof a thumb piece 23 slidably supported by a handle 22 secured to the outer surface of the door as by means of bolts 2|. The upper end of the handle 22 has a slot 24 in which is mounted the thumb piece 23 which may be formed of plastic. The thumb piece 23 is provided, at its lower end, with laterally extending ribs 25 which slidably fit in grooves 26 provided in the opposed inner surfaces of the walls of the slot 24. The grooves 26 extend from the inner surface of the handle and terminate at their outer ends in shoulders 26. The ribs 25 are shorter than the grooves 26; and inward movement of the thumb piece 23 is limited by the engagement of the forward face thereof against the door and outward movement of the thumb piece is limited by the engagement of the outer ends of the ribs 25 against the shoulders 26. The thumb piece 23 `has a hole 21 into Which the outer end of the stem 3| projects. It is seen that inward movement of the thumb piece 23 pushes the plunger yoke Il inwardly and serves to retract the latch bolt I5.

Referring now more specically to the construction of the plunger, the same, as stated, comprises the yoke I'I, the sleeve or collet 30 and the stem 3|. The members 3|) and 3| are adjustably telescoped one into the other. The two members are provided with interlocking means which permit adjustment therebetween when the two members are pressed together with greater pressure than that exerted by the maximum pressure of the spring I5 in forcing the bolt I5 to latching position, the interlocking means, however, being so constructed and arranged that, during the normal operation of the latch, the adjustment between the collet 3|) and the stem 3| is not disturbed. In the present illustrative disclosure, the collet 30 is in the form of a sleeve, the inner end of which is provided with lugs 32 which extend through slots in the cross portion of the yoke Il, the ends of the lugs being peened or staked so as to hold the by the stem instead of by the door handle. Alatch unit would still be useful for` installation parts in place. The collet 30 has a long slot 34 and two shorter slots 35 thus providing three resilient ngers 36, each of which is provided with an internal, annular rib or tooth 31 which is generally V-shaped in cross section. The

outer surfaces 38 of the teeth are inclined to the axis of the sleeve at a greater angle than are the inner surfaces 39 of the teeth (see Fig. 4). The stem 3| is provided with a series of circumferential ribs or ridges 40'whi'ch are generally V-shaped in cross section, the outer surfaces of the ribs being inclined correspondinglyto. the inner surfaces 39 of the teeth, and the inner surfaces of the ribs being inclined correspondingly to the outer surfaces 38 of the teeth. The collet and stem are of such diameters that the teeth 3lon the ngers 3E are adapted to engage in the grooves between the ribs 4S, as shown in Fig; 4.

With the arrangement described, when it is desired to mount the structure on the door, the latch mechanism is installed on the inner side ofl the door with the collet 39 extending into bore 2li in the door. The inner end of the stem 3f" may be pushed into the collet 39 to a limited extent, this being permissible as the teeth 3l' on the fingers 36 of the collet will ratchet over the ribs 46. Assuming that the effective length of the plunger is excessive, when the handle with the thumbk piece 23 thereon is being installedV on the outer surface of the door, it may happen that, when the thumb piece 23 is in its forwardmost position, the plunger may be so long that the lever I3 is forced into dot-dash line position` I3 in which it engages the rear wall of casing I9. As screws 2| are tightened, stem 3l is forced further into collet 3G Whose resilient fingers 36 snap into the grooves between the ribs 40 of the stem 3|. Since spring i6 is too weak to, force the collet forwardly over the stem si, the. lever I3 remains at position i3. After the handle is installed upon the door, the thumb piece 23 is pushed rearwardly against the door thereby forcing the stem rearwardly into the collet thereby automatically reducing the length of the plunger to such value that, when the thumb piece is released, the spring i6 will return the bolt I5 to latching position.

The latch unit may be considered as comprising' the casing It and the parts permanently attached thereto and also the stem 3l which could be assembled partway into the collet 30 before the casing iQ is attached to a door. This switch unit is not limited in its application merely to doors to which handles earring thumb pieces are to be applied. It may be applied to doors of varying thickness regardless of the kind of handle to be attached on the outside of the door. For example, the stem 3l could be provided with an operating knob which is retained The with doors of varying thickness because, for sake of appearance, it is desirable that the operating knob extend no further from the outside of the door than necessary. The present switch unit provides for the normal location of the operating knob or push piece the same distance from outside of the door regardless of thickness of the door within the limits ordinarily encountered in architectural or cabinet work.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof,

it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of' the generic and specific features of the invention herein described and al1 statements of the scopeof the invention which, as a matter of language, might be said to fall therebetween.

I claim as my invention:

1. In a door latch assembly of the type comprisingV a latch having a spring projectedv bolt and means limiting retractive movementl of the bolt, said: latch being' constructed and arranged for mounting on one side of" a door, andan op'- erator therefor including a' pushl pieceY constructed and arranged for mounting on the opposite side of .the door, the combination therewith of motion transmitting means extending between the latch and push piece comprising'a pair of telescopically cooperating parts one of which is provided with a series, of ribs spaced by V-grooves and the other of which is provided with resilient fingers for engaging the grooves, said ribs and fingers having engaging surfaces so inclined that the force necessary to contract the means exceeds the force of the bolt projecting spring.

2. In a door latch assembly of the type comprising a latch having a spring projectedy bolt and means limiting retractive movement of the bolt, said latch being constructed and arranged for mounting on one side of a` door, and an operator therefor including a push piece constructed and arranged for mounting on the opposite side of the door, the combination therewith of motion transmittingV means extending between the latch and push piece comprising tclescopically-engaging members, one of which is a stem having a series of annular ribs each of-which is bounded by conical surfaces, the outer surface of each rib being at greater inclination to the axis of the stem than the inner surface of the rib, and the other member being a collet of tubular construction and being slotted to provide a plurality of resilient fingers, each linger being provided with an internal rib bounded by surfaces adapted to mate with the surfaces of the grooves between the ribs of the stem, the resistance oiered by the collet lingers to displacement of the stem inwardly relative to the collet being greater than the reactive force of the bolt projecting spring as the stem is pushed toward the latch to effect. retraction of the latch bolt. JOHN D. CARROLL.

REFERENCES CITED The following references are of record in the le of this patent:

UNITEDy STATES PATENTS Lindstrom et al. Nov. 29, 1938 

